Heat-sealing device and filling-packing machine provided therewith

Abstract

A heat-sealing device is capable of properly changing a pushing force applied from the heat-sealing roll to the packing film in accordance with the feeding rate of the packing film. A heat-sealing device for holding an elongated packing film with a pair of heat sealing rolls arranged in parallel to each other to form a heat sealed portion includes a pushing means made of a first cylinder and a second cylinder for holding the packing film with the heat-sealing rolls by pushing through an action of fluid pressure, a fluid pressure controlling means capable of adjusting the fluid pressure of the pushing means, and a superior controlling means for rendering a total value of pushing forces of the first cylinder and second cylinder into a proper pushing force and operating one or both of the first cylinder and the second cylinder in accordance with the feeding rate of the packing film.

The invention claimed is: 
     
       1. A heat-sealing device for holding an elongated packing film fed in a longitudinal direction and arranged at an opposing state of adhesive layers or sealant layers with a pair of heat-sealing rolls disposed in parallel to each other and extending in a first axial direction to form a heat-sealed portion, comprising:
 a pusher made of a first cylinder and a second cylinder arranged on a same axial line to hold the packing film with the heat-sealing rolls by pushing at least one of the heat-sealing rolls to the other heat-sealing roll through an action of fluid pressure, the same axial line of the first cylinder and the second cylinder extending in a second axial direction perpendicular to the first axial direction of the heat-sealing rolls, 
 a fluid pressure controller configured to adjust the fluid pressure of the pusher, and 
 a superior controller configured to calculate a calculated pushing force from input values of a variety of the packing film and filling condition and to control the fluid pressure controller so that a total value of pushing forces of the first cylinder and second cylinder is made equal to the calculated pushing force and one or both of the first cylinder and the second cylinder are operated in response to a change in a feeding rate of the packing film. 
 
     
     
       2. The heat-sealing device according to  claim 1 , wherein the superior controller operates only the first cylinder when the feeding rate of the packing film is not more than a predetermined rate and controls the fluid pressure controller so as to offset a shortage of the pushing force of the first cylinder with the pushing force of the second cylinder when the feeding rate of the packing film exceeds the predetermined rate. 
     
     
       3. A filling-packing machine comprising:
 a vertical sealer to form a vertical sealed portion continuously extended in a longitudinal direction of one or two elongated packing films at a side edge portion of the packing film continuously or intermittently fed in the longitudinal direction and arranged at an opposing state of adhesive layers or sealant layers to render the packing film into a cylindrical form, and 
 a lateral sealer to form lateral sealed portions, which are extended in a direction perpendicular to the longitudinal direction of the packing film over a full width of the packing film to seal a packing material intermittently or continuously filled in the cylindrical packing film provided with the vertical sealed portion, at intervals in the longitudinal direction of the packing film, 
 wherein the vertical sealer and/or the lateral sealer are provided with a heat-sealing device as claimed in  claim 2 . 
 
     
     
       4. A filling-packing machine comprising:
 a vertical sealer to form a vertical sealed portion continuously extended in a longitudinal direction of one or two elongated packing films at a side edge portion of the packing film continuously or intermittently fed in the longitudinal direction and arranged at an opposing state of adhesive layers or sealant layers to render the packing film into a cylindrical form, and 
 a lateral sealer to form lateral sealed portions, which are extended in a direction perpendicular to the longitudinal direction of the packing film over a full width of the packing film to seal a packing material intermittently or continuously filled in the cylindrical packing film provided with the vertical sealed portion, at intervals in the longitudinal direction of the packing film, 
 wherein the vertical sealer and/or the lateral sealer are provided with a heat-sealing device as claimed in  claim 1 .